I will admit, I have been surprised how much they have enjoyed sharing a room. They are good friends!
When it came to decorating, I wanted their room to look nice but I didn't want to spend a lot of money because I know eventually I would like to have our 3 year old daughter share with the baby sister.
Nightstands- both kids have their own nightstand for their own personal things. One was free the other was $7 at a thrift store, I refinished them.
Duvet Covers- I made them out of flat sheet and ribbon (less than $20 each)
Pillow Shams- Bought the blue one at Homegoods, sewed the pink one.
Accent Pillows- Pottery Barn and Homegoods
Lamp- Our 5 year old wanted an orange lamp. He picked it out at Hobby Lobby.
Rug- Pottery Barn
Nightstand accessories (boxes and mailbox)- Hobby Lobby and Pottery Barn
Big letters- clearance from Hobby Lobby, I painted them white
Their room is small, I didn't want to add a dresser. We put the clear plastic drawers in their closet and they work perfectly for their little clothes.